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  • Author or Editor: G. Rezaei Behbehani x
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Abstract  

The interaction of Cu2+ to the first 16 residues of the Alzheimer’s amyloid β peptide, Aβ(1–16) was studied by isothermal titration calorimetry at pH 7.2 and 37°C in aqueous solution. The Gholamreza Rezaei Behbehani (GRB) solvation model was used to reproduce the enthalpies of interactions of Aβ(1–16) with glycine, Gly+Aβ(1–16), and Cu2+ ions, Cu2+ +Aβ(1–16), over the whole range of Cu2+ concentrations. The binding parameters recovered from the solvation model were attributed to the structural change of Aβ(1–16) due to the glycine and Cu2+ interactions. It was found that there is a set of two identical binding sites for Cu2+ ions. p=2 indicates that the binding has positive cooperativity in the two binding sites. Aβ(1–16) structure is destabilized greatly as a result of binding to Cu2+ ions.

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A thermodynamic study on the binding of magnesium with human growth hormone

Consideration of the new extended coordination model solvation parameters

Journal of Thermal Analysis and Calorimetry
Authors:
G. Rezaei Behbehani
and
A. Saboury

Abstract  

The thermodynamic parameters underlying the binding of Mg2+ to the hydrophobic core of human growth hormone, hGH, are determined using isothermal titration calorimetry. The interaction between Mg2+ and hGH (35 μM) was studied at 27°C in NaCl solution. A new solvation model was used to reproduce the enthalpies of Mg2+-hGH interaction over the whole Mg2+ concentrations. The solvation parameters recovered from the new salvation model, were correlated to the structural changes of hGH due to the metal ion interaction.

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Abstract

A Thermodynamic study on the interaction Jack bean urease, JBU, with Cu2+ ion was studied by isothermal titration calorimetry (ITC) at 300 and 310 K in 30 mM Tris buffer solution, pH 7.0. The heats of JBU + Cu2+ interactions are reported and analyzed in terms of the extended solvation theory. It was indicated that there are a set of 12 identical and non-cooperative sites for Cu2+ ion. The binding of Cu2+ ion with JBU is exothermic with dissociation equilibrium constants of 284.883 and 345.855 μM at 300 and 310 K, respectively.

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Abstract  

Binding properties of myelin basic protein (MBP) from bovine central nervous system due to the interaction by divalent magnesium ion (Mg2+) was investigated at 27°C in aqueous solution using isothermal titration calorimetry (ITC) technique. An extended solvation model was used to reproduce the enthalpies of Mg2+-MBP interaction over the whole Mg2+ concentrations. It was found that there is a set of two identical and noninteracting binding sites for Mg2+ ions. The dissociation equilibrium constant is K d=45.5 μM. The molar enthalpy of binding site is identical for both sites; ΔH=−15.24 kJ mol−1. The solvation parameters recovered from the solvation model were attributed to the structural change of MBP due to the metal ion interaction.

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Abstract

In this article, a thermodynamic study on the interaction of Jack bean urease, JBU, with and ions were studied by isothermal titration calorimetry (ITC) at 300 and 310 K in 30 mM Tris buffer solution, pH 7.0. The heats of and interactions are reported and analyzed in terms of the extended solvation model. It was indicated that there are a set of 12 identical and non-cooperative sites for and ions. The binding of and ions with JBU are exothermic with association equilibrium constants of 5415.65 and 4368.15 for and 2389 and 2087 for at 300 and 310 K, respectively.

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Abstract  

The interaction of myelin basic protein (MBP) from the bovine central nervous system with divalent nickel ion was studied by isothermal titration calorimetry at 37 and 47 °C in Tris buffer solution at pH = 7. The new solvation model was used to reproduce the heats of MBP + Ni2+ interaction over the whole Ni2+ concentrations. It was found that MBP has three identical and independent binding sites for Ni2+ ions. The intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 89.953 μM, −14.403 kJ mol−1 and 106.978 μM, −14.026 kJ mol−1 at 37 and 47 °C, respectively. The binding parameters recovered from the new solvation model were correlated to the structural changes of MBP due to its interaction with nickel ion interaction. It was found that in the low and high concentrations of the nickel ions, the MBP structure was destabilized.

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Abstract  

A method based on Isothermal Titration Calorimety (ITC) is described for the thermodynamic assay of jack bean urease. Inhibitory activity of cyanide ion was examined against jack bean urease (JBU), at 27 and 37 oC in 30 mM Tris buffer of pH = 7. The binding parameters of the CN + JBU complexation have been calculated. It was found that in the low and high concentrations of the cyanide ions, the JBU structure was destabilized, resulting in a decrease in its biological activity.

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Journal of Thermal Analysis and Calorimetry
Authors:
G. Rezaei Behbehani
,
A. Saboury
,
S. Tahmasebi Sarvestani
,
M. Mohebbian
,
M. Payehghadr
, and
J. Abedini

Abstract  

The thermodynamic parameters of interaction between theophylline and Human Serum Albumin (HSA) in buffer solution (30 mM) of pH = 7 at 27 °C was investigated by isothermal titration calorimetry (ITC). The thermodynamic quantities of the binding mechanism, the number of binding sites (g), the dissociation binding constant (K d), the molar enthalpy of binding (ΔΗ) and other thermodynamic parameters can be obtained by the extended solvation theory.

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